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Updated: Jul 17, 2026

Integration of Miniaturized Solid Phase Extraction and LC-MS/MS Detection of 3-Nitrotyrosine in Human Urine for Clinical Applications
Published on: July 14, 2017
Disposition of protein-bound 3-nitrotyrosine in rat plasma analysed by a novel protocol for HPLC-ECD
Yoshiaki H Hitomi1, Junna Okuda, Hirohito Nishino
1Department of Environmental and Preventive Medicine, Graduate School of Medical Science, Kanazawa University, 13-1, Takaramachi, Kanazawa, Ishikawa, Japan.
Abstract:
3-Nitrotyrosine (NTyr) is considered as a biomarker of the generation of reactive nitrogen species (RNS). However, it is still difficult to determine its concentration in biological samples. To develop a reliable and high-throughput method, we optimized the conditions for high performance liquid chromatography and electrochemical detection (HPLC-ECD). The best separation of NTyr was achieved using a highly acidic mobile phase (pH 2.5). The concentration of protein-bound NTyr in plasma protein was 593.6 +/- 53.8 fmol/mg in rats treated with lipopolysaccharide (LPS) and 114.4 +/- 27.6 fmol/mg in control. After intravenous administration of in vitro-nitrated plasma protein, NTyr concentration decreased; the half-life was 63.4 +/- 16.8 h. Consistently, protein-bound NTyr concentration in plasma after LPS treatment declined gradually, but was detectable for 1 week. Our protocol is reproducible and suitable for analysing multiple clinical samples to study RNS production in vivo.

